In-line storm water filter

ABSTRACT

An in-line filter and method for reducing the solids content of a liquid passing through a storm sewer line. The frame of the filter is provided with a screen and optionally, filter media, and is decreased in size until the frame is small enough to fit into the storm sewer line into which liquids carrying solids and pollutants pass. The frame is then expanded into frictional engagement against the inside surface of the line.

BACKGROUND OF THE INVENTION

[0001] The present invention relates to an apparatus and method forreducing the pollutants in storm water runoff passing through a stormsewer line. More specifically, the present invention relates to anapparatus for easily mounting a reusable filter inside a line forremoving pollutants from a liquid passing through a storm sewer line.

[0002] The present invention has particular application to disturbedconstruction sites, where rain on bare ground has the result of washinglarge quantities of solids from the site and into the storm drainagesystem. In addition to the undesirable removal of soil from the site,the solids washed from the site can settle in the storm sewers and/orreceiving streams or channels, and can have the result of interferingwith the function of the receiving streams or channels and/orcontaminating the receiving streams or channels. Of course the solidsthat wash off of the construction site are often not just dirt andparticulate solids—it is not uncommon for the run-off to include trash,building materials, and other solids that can do more than justinterfere with the function of the drain and/or sewer.

[0003] For these, and other reasons, it is desirable to prevent entry ofthe solids in the run-off from disturbed construction sites. Theimportance of preventing the entry of solids from such sites into thestorm sewer lines has even prompted regulatory action, and the presentinvention therefore provides a method to aide in compliance withEnvironmental Protection Agency regulations as set out in Title 40 ofthe Code of Federal Regulations, and specifically, the requirements ofthe National Pollution Discharge Elimination System regulations.

[0004] One method that has been used to address this problem is to builda wood frame, staple fabric over the frame, position the frame over theopening of the storm sewer in the inlet box, and brace the frame againstthe inlet box walls. Although this construction can function to reducethe solids entering the drain, its relatively bulky construction makesit difficult to remove collected pollutants from the inlet box and toreplace and/or maintain the fabric, which can compromise itseffectiveness. Further, it must be purpose-built on-site and cannot beeasily re-used.

[0005] There is, therefore, a need for improvements in reducing thevolume of pollutants contained in the water washing off a disturbedconstruction site, and it is an object of the present invention toprovide such an improvement, specifically in the form of a filter thatis adapted to fit inside the storm sewer line connected to the inletbox.

[0006] However, those skilled in the art will understand from thefollowing description that the present invention, while being originallyintended for application in the above-described environment, has broaderapplication in that it is useful in any environment in which it isdesired to reduce the solids content of a liquid that is passing througha line. It is, therefore, an object of the present invention to providean improved in-line filter for use in wide variety of applications inreducing the solids content of a liquid passing through a line.

[0007] Another object of the present invention is to provide anapparatus and method for reducing the solids content of a liquid passingthrough a line that is easily and quickly installed before or as soon asthe line is put into service.

[0008] Another object of the present invention is to provide anapparatus and method for reducing the solids content of a liquid passingthrough a line that is durable and reusable.

[0009] Another object of the present invention is to provide anapparatus and method for reducing the solids content of a liquid passingthrough a line that is easily cleaned and maintained.

[0010] Another object of the present invention is to provide anapparatus and method for in-line filtering of solids from a liquidpassing through the line that functions to allow the liquid to pass onthrough the line even when the filter of the present invention hastrapped sufficient solids as to occlude a portion of the filter area.

[0011] Another object of the present invention is to provide anapparatus and method that is adapted for easily switching the filtermaterial mesh size and/or effective opening so as to remove the desiredamount of solids from the liquid passing through the line and/or toremove solids of certain sizes from the liquid passing through the line.

[0012] Yet another object of the present invention is to provide anapparatus and method that is adapted to provide for a variable by-passarea easily and economically so as to allow for adjustable by-pass flowto coincide with varying stages of development and pollutant levels inthe storm water runoff.

[0013] Other objects, and the advantages, of the present invention willbe made clear to those skilled in the art by the following descriptionof the presently preferred embodiments thereof

SUMMARY OF THE INVENTION

[0014] These objects are achieved by providing an in-line filter forreducing the pollutant content of a liquid passing through a storm linecomprising a first frame adapted for frictionally engaging the insidesurface of a line and a second frame having a size and shape that allowsthe second frame to fit into the first frame after the size of the firstframe is increased by expanding the first frame outwardly to receive thesecond frame therein. The filter media is retained between said firstand second frames and an adjustment nut and bolt are mounted on thefirst frame for decreasing the size of the first frame after the secondframe is received therein until the outside diameter of the first frame,having the second frame and the filter media assembled thereto, is smallenough to fit into and frictionally engage the inside surface of theline.

[0015] The present invention also provides a method for reducing thesolids content of a liquid passing through a line comprising the stepsof increasing the size of a first frame to accept a second frametherein, said second frame supporting the filter media, decreasing thesize of the first frame to a size small enough to fit within the line inwhich it is desired to reduce the solid content of a liquid passingthere through, and increasing the size of the first frame until thefirst frame frictionally engages the inside diameter of the line.

[0016] These objects are also achieved by providing an in-line filterfor reducing the pollutant content of a liquid passing through a linecomprising a single frame adapted for frictionally engaging the insidesurface of a line. The size of the first frame is increased by expandingthe frame outwardly to frictionally engage the inside surface of a line.The filter media is retained between said frame and the inside surfaceof the line and an adjustment nut and bolt are mounted on the frame fordecreasing and increasing the size of the frame until the outsidediameter of the frame, is small enough to fit into the line and largeenough to frictionally engage the inside surface of the line and retainthe screen and/or filter media.

[0017] The present invention also provides a method for reducing thesolids content of a liquid passing through a line comprising the stepsof increasing the size of the frame to the size of the line, said frameis covered with filter fabric and then covered with a stiff screen thatis wrapped around said frame to hold the filter fabric in place,decreasing the size of the frame to a size small enough to fit withinthe line in which it is desired to reduce the solid content of a liquidpassing there through, and increasing the size of the frame until theframe and filter media frictionally engage the inside diameter of theline.

BRIEF DESCRIPTION OF THE DRAWINGS

[0018]FIG. 1 is an elevation view of a preferred embodiment of anapparatus for reducing the solid content of a liquid passing through aline that is constructed in accordance with the teachings of the presentinvention and that is frictionally engaging the inside surface of astorm drain pipe.

[0019]FIG. 2 is a sectional view of the apparatus of FIG. 1 taken alongthe lines A-A in FIG. 1.

[0020]FIG. 3 is a detail view of the adjustment nuts and bolt of apresently preferred embodiment of the embodiment shown in FIG. 1.

[0021]FIG. 4 is a sectional view of a second embodiment of the apparatusof the present invention.

[0022]FIG. 5 is a detail view of the adjustment nuts and bolt of asecond embodiment of the apparatus of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0023] Referring to the figures, a preferred embodiment constructed inaccordance with the teachings of the present invention is indicatedgenerally at reference numeral 10. The apparatus 10 comprises a firstframe 12 adapted for fitting into and engaging the inside surface of astorm sewer pipe 14 of conventional construction. By referring to FIG.2, it can be seen that the first frame 12 is concentric with a secondframe 16 and that a layer of wire mesh 18 is sandwiched between the twoframes 12, 16. In the particular embodiment 10 shown in FIGS. 1-3, thewire mesh 18 serves as a backing for a section of filter media 20 thatis also sandwiched between the two concentric frames 12, 16 and thatacts as a filter to reduce the solids content of liquid passing throughthe drain pipe 14.

[0024] It will be noted that, in the preferred embodiment shown, thefilter media 20 does not necessarily cover the entire layer of wire mesh18 or the second frame 16. When the apparatus 10 of the presentinvention is placed into the drain pipe 14 with the first frame engagingthe inside surface of pipe 14, the filter media 20 functions to filterthe solids from the water passing there through, with the resultingaccumulation of solids at the upstream side of the apparatus 10.Although not immediately apparent from the drawings, the size of secondframe 16 is fixed, i.e., not adjustable. In the case of the round drainpipe 14 shown in the figures, because the drain pipe 14 is round, it isthe diameter of the second frame 16 that is not adjustable, but thoseskilled in the art who have the benefit of this disclosure willrecognize that the line in which the apparatus 10 is utilized need notbe round such that the apparatus 10 may be shaped in any shape asrequired by the shape of the particular line in which the apparatus 10is to be positioned. It is for this reason that the presentspecification refers to the “size” of the frames 12, 16 rather thanusing words such as “~diameter,” which carry connotations of shape, todescribe the frames 12 and 16. By contrast, the size of first frame 12can be changed, and in particular, as best shown in FIG. 3, first frame12 is provided with integral collars 22A and 22B, one on each free endof frame 12, having an adjustment bolt 24 and nut 26 positioned thereon.In the particular embodiment shown in FIG. 3, the adjustment bolt 24 isthreaded and extends through collar 22B, adjustment nut 26 and collar22A and into a fixed threaded nut 28 that is fixedly attached to collar22A. Collar 22A and threaded fixed nut 28 is arranged such that therotation of bolt 24 causes collar 22B to travel along the length of bolt24, thereby decreasing the size of the first frame 12 to which collars22A and 22B are mounted. Similarly, the size of first frame 12 isincreased by rotating bolt 24 until the head of the bolt 24 disengagesthe collar 22B and creates a space between the head of bolt 24 andcollar 22B. Then, by rotation of the adjustment nut 26 while holding thebolt 24 fixed, collar 22B travels along the length of bolt 24, therebyincreasing the size of the first frame 12 to which collars 22A and 22Bare mounted.

[0025] Those skilled in the art will, however, recognize that the sizeof first frame 12 can be changed in a number of ways that do not involvethe adjustment bolt 24 and nut 26 such that the present invention shouldnot be considered restricted in its scope to the particular sizeadjusting means shown in FIG. 3. It does happen, however, that athreaded adjustment bolt such as the bolt 24 is particularly useful forthis purpose because it easily allows for varying degrees of change insize, thereby insuring secure engagement of the first frame 12 and theinside surface of the drain pipe 14. Further, in the particularembodiment shown, the threaded adjustment bolt 24 is provided with anadjustment nut, 26 that rides on the threads of bolt 24. When theapparatus 10 of the present invention is inserted into the storm drainpipe 14, rotation of adjustment nut 26 toward the collar 22B causesmovement of collar 22B relative to bolt 24, and because collar 22B isintegral with first frame 12, the movement of collar 22B relative tobolt 24 causes the size of first frame 12 to increase so as to securelyengage the inside surface of the drain pipe 14.

[0026] In the preferred embodiment shown in the figures, andspecifically by reference to FIG. 2, it can be seen that the first andsecond frames 12, 16 are both “C”-shaped when viewed in section. This“C”-shape of first and second frames 12, 16 functions to resist movementof second frame 16 relative to first frame 12, thereby affirmativelyretaining the wire mesh 18 and filter fabric 20 therebetween. It will berecognized, however, by those skilled in the relevant art that the samegoal is accomplished by rolling the edge of one or the other (or both)of first and second frames, 12, 16 to create a lip along the edge of theframes 12, 16 and/or by a detent or nipple formed in one or the other offrames 12, 16 to provide a snap or friction fit between frames 12, 16.

[0027] Referring now to FIGS. 4-5, there is shown an alternateembodiment of the apparatus 10 of the present invention in which likenumerals are used to identify parts corresponding to the component partsof the embodiment shown in FIGS. 1-3. In this alternate embodiment,instead of two “C”-shaped frames, one frame 12 is covered with filtermedia 20 and the wire mesh 18 wrapped around the exterior surface andinto the interior surface of frame 12. Just as in the embodiment shownin FIGS. 1-3, the size of the frame 12 of the embodiment shown in FIGS.4-5 can be changed. In particular, and as best shown in FIG. 5, frame 12is provided with integral guides or collars 23A and 23B, one on eachfree end of frame 12, having an adjustment bolt 24 and nut 26 positionedthereon. In the alternate embodiment shown in FIG. 5, the adjustmentbolt 24 is threaded and extends through the guide or collar 23B,adjustment nut 26 and guide or collar 23A, and into a threaded nut 28that is fixedly attached to guide or collar 23A. Guide, or collar, 23Aand threaded fixed nut 28 are arranged such that the rotation of bolt 24causes guide or collar 23B to travel along the length of bolt 24,thereby decreasing the size of the frame 12 to which guides or collars23A and 23B are mounted. Similarly, to increase the size of the frame12, bolt 24 is rotated until the head of bolt 24 disengages the guide orcollar 23B and creates a space between the adjustment bolt 24 and collar23B. Then, by rotation of adjustment nut 26 while holding the bolt 24fixed, guide or collar 23B is caused to travel along the length of bolt24, thereby increasing the size of the frame 12 to which guides orcollars 23A and 23B are mounted.

[0028] Those skilled in the art who have the benefit of this disclosurewill recognize that certain changes can be made to the component partsof the apparatus of the present invention without changing the manner inwhich those parts function to achieve their intended result. All suchchanges, and others which will be clear to those skilled in the art fromthis description of the preferred embodiments of the invention, areintended to fall within the scope of the following, non-limiting claims.

What is claimed is:
 1. An in-line filter for reducing the solids contentof a liquid passing through a storm sewer line comprising: a frameadapted for frictionally engaging the inside surface of a storm sewerline; by expanding outwardly into engagement with the inside surface ofthe storm sewer line; a screen and/or filter fabric retained on saidframe; and an adjustment nut and bolt mounted on said frame fordecreasing the size of said frame until the outside diameter of saidframe, having said screen and/or filter fabric assembled thereto, issmall enough to fit into the storm sewer line and then increasing thesize of said frame until said frame is large enough to frictionallyengage the inside surface of the storm sewer line.
 2. The in-line filterof claim 1 wherein said frame additionally comprises two collars orguides for receiving said adjustment bolt therethrough.
 3. The in-linefilter of claim 2 additionally comprising a nut for riding on said boltfor bearing against a collar or guide on said frame that, when turned,causes said frame to expand outwardly.
 4. The in-line filter of claim 1wherein said frame is provided with means for resisting undesiredmovement of said screen and/or filter fabric relative to said frame andinside surface of said storm sewer line.
 5. The in-line filter of claim4 wherein said movement resisting means is accomplished by frictionallyengaging the inside surface of said storm sewer line with the screenand/or filter fabric and said frame with said outward expansion.
 6. Thein-line filter of claim 1 additionally comprising an inner frame memberadapted for supporting a screen and/or filter fabric.
 7. A method forreducing the solids content of a liquid passing through a linecomprising the steps of: increasing the size of a first frame to accepta second frame therein, said second frame supporting a screen and/orfilter fabric; decreasing the size of said first frame to a size smallenough to fit within the line in which it is desired to reduce the solidcontent of a liquid passing therethrough; and increasing the size of thefirst frame until the first frame frictionally engages the insidediameter of the line.
 8. The method of claim 7 additionally comprisingresisting movement of the inner frame relative to the said first frame.